优化房间点赞同步为增量更新策略

src/lib/roomRepository.test.ts

@@ -0,0 +1,58 @@
+import { describe, it, expect } from "vitest";
+import { diffRoomLikes } from "@/lib/roomRepository";
+
+describe("diffRoomLikes", () => {
+  it("returns incremental create/delete changes", () => {
+    const current = {
+      r1: ["u1", "u2"],
+      r2: ["u3"],
+    };
+    const updated = {
+      r1: ["u1", "u3"],
+      r3: ["u2"],
+    };
+
+    const result = diffRoomLikes(current, updated);
+
+    expect(result.toDelete).toEqual(
+      expect.arrayContaining([
+        { userId: "u2", restaurantId: "r1" },
+        { userId: "u3", restaurantId: "r2" },
+      ]),
+    );
+    expect(result.toCreate).toEqual(
+      expect.arrayContaining([
+        { userId: "u3", restaurantId: "r1" },
+        { userId: "u2", restaurantId: "r3" },
+      ]),
+    );
+  });
+
+  it("deduplicates repeated user likes", () => {
+    const current = {
+      r1: ["u1", "u1", "u1"],
+    };
+    const updated = {
+      r1: ["u1"],
+    };
+
+    const result = diffRoomLikes(current, updated);
+
+    expect(result.toCreate).toEqual([]);
+    expect(result.toDelete).toEqual([]);
+  });
+
+  it("returns empty arrays when likes are unchanged", () => {
+    const current = {
+      r1: ["u1", "u2"],
+    };
+    const updated = {
+      r1: ["u1", "u2"],
+    };
+
+    const result = diffRoomLikes(current, updated);
+
+    expect(result.toCreate).toEqual([]);
+    expect(result.toDelete).toEqual([]);
+  });
+});